I have had a problem with my IBM X41 – ever since I have started using Ubuntu 7.10 (after a nice upgrade from 7.04), whenever the lid was closed, and reopened – the display would have flickered for a short while (while the lid is up) and then blank completely.
My (ugly) workaround was to force the computer to sleep whenever it happened. It seemed to be a workaround good enough for most cases. On some cases, the laptop would do just the same as it was placed in its docking station.
I have found an Ubuntu bug here, which seems to expose this problem too. It exposed few additional problems as well. The error message I got (through SSH, of course) when viewing the logs it said that the video card detected pipe A to be the active pipe, that it stopped using pipe B (which appeared to be the internal one) and that it decided to disable clone mode. Wow. I just lost my internal LCD. Connecting an external display, I get the whole picture working just fine, however, I cannot use the laptop like that.
After a major struggle with various i810 options, I have looked and found an option to disable Power Management. I have done so, according to the note here, and it solved all my problems in this area – for now.